HarmonyOS 防截屏功能如何实现

参考demo：

aboutToDisappear(): void {
  let windowClass: window.Window | undefined = undefined;
  window.getLastWindow(getContext(this)).then((win) => {
  this.window = win
})
window.getLastWindow(getContext(this), (err: BusinessError, data) => {
  const errCode: number = err.code;
  if (errCode) {
    console.error('Failed to obtain the top window. Cause: ' + JSON.stringify(err));
    return;
  }
  windowClass = data;
  console.info('Succeeded in obtaining the top window. Data: ' + JSON.stringify(data));
  setWindowPrivacyMode(windowClass, true)
});
}


export function setWindowPrivacyMode(windowClass: window.Window, isPrivacyMode: boolean) {
  // try {
  windowClass.setWindowPrivacyMode(isPrivacyMode
    /*, (err: BusinessError) => {
    if (err) {
      console.error('Failed to set the window to the privacy mode. Cause:'+ JSON.stringify(err));
      return;
    }
    console.info('Succeeded in setting the window to the privacy mode.');
  }*/
  );
  console.info(`setWindowPrivacyMode 已执行`);
  // } catch (exception) {
  //   console.error('Failed to set the window to the privacy mode. Cause:'+ JSON.stringify(exception));
  // }
}